You might not realize it, but most of the processed foods you buy are Kosher-certified. Even your Bac-os (ah, trans fat: Is there anything you can’t do?).

There are a number of Kosher certifying agencies—so many, in fact, that I often see friends posting pictures of a certification asking if it’s reliable because it’s so hard even for kosher-keepers to keep track of them all.

The most common certifying agency is the OU, which stands for the kosher certification arm of the Orthodox Union. Take a look in your pantry. You’re bound to see their symbol, which many mistake for a trademark: an O with a U inside. You can find it and others like it on the front of packages of just about anything: cookies, cake mixes, cereal, and dry goods like rice, beans, and barley.

But back to those glorious trans fats. An unintended victim of the new crusade to banish trans fats from our diet may be kosher-keepers. The laws governing what Orthodox Jews can and cannot eat are varied, but there are some old standards that virtually everyone knows: Don’t eat pork, for example, or shellfish. We also don’t mix meat and dairy. Most Orthodox Jews wait several hours after they eat meat to eat anything with dairy in it (the number of hours depends on individuals’ customs). If I had chicken for dinner, I can’t have a cake made with real butter for dessert.

No Oreos For You

In a fascinating book published in 2010, Sue Fishkoff discusses the phenomenon of kosher certification going mainstream. She writes:

Oreos had always been forbidden in an Orthodox home because they were made with lard. Joe Regenstein, a food science professor and kosher industry expert at Cornell University, says every Jewish child in his hometown of Newark, New Jersey, ‘knew’ the nearby Nabisco plant ‘was a lard house,’ that the cookies it made were filled with forbidden pork fat. Kosher substitutes like Hydrox cookies, produced since 1908 by Sunshine Biscuits, didn’t have the same taste, crunch, or cachet.
Years later, as a faculty member at Cornell, he found himself serving on a University advisory Council with the vice president from Nabisco. Jokingly, he asked the man what it would cost for the company to go kosher. Six months later, executive came back with a figure: $8 million, too much to consider.
By the 1990s, however, the product is no longer unthinkable. Saturated fats were on the outs, food manufacturers replacing them with trans fats (considered healthier at the time). Nabisco, too, replaced the lard in its food projects with vegetable oil.

With the expulsion of lard from America’s food factories, suddenly Orthodox Jews were able to eat the foods their neighbors had been enjoying for years. That luxury, eating foods not made from scratch, may be over for America’s Jews if the war on trans fats brings back lard and butter. While the latter wouldn’t make foods totally verboten, it would seriously hamper the culinary choices Jews have while consuming meat.

The Trans Fat Ban Is Not Only Offensive But Stupid

Religious Jews might not be a large contingent of America’s consumers, but we are a quite-vocal one. Ten years ago, Kraft made plans to alter the recipe for its Stella D’Or Swiss fudge cookies and faced a backlash from religious Jewish enclaves across America. TheNew York Timesreported on the company’s decision to change its recipe to include dairy, which would have prevented religious Jews from eating the cookies after a meat meal, discussing the backlash delivery drivers heard about from Jewish customers along their routes.

The most galling part of the war on trans fats, and a possible re-emergence of lard, is how utterly unscientific so much of food science is. In our lifetimes, we’ve seen foods banned from America’s tables only to later be welcomed back with open arms (full fat, eggs, and salt are just a few examples). At the time of its inclusion into American diets, trans fats were heralded as a revolution in food science. In an NPR piece on the history of Crisco, the wayback machine of our collective memories is activated all the way back to the 1980s:

But did you know that in the 1980s, health activists actually promoted oils containing trans fats? They considered such oils a healthy alternative to the saturated fats found in palm oil, coconut oil, or beef fat. In 1986, for instance, the Center for Science in the Public Interest (CSPI), described Burger King’s switch to partially hydrogenated oils as ‘a great boon to Americans’ arteries.’

Predictably, NPR then goes on to deem the science on trans fat settled. I’m not a trans fat truther, but a glance at the past staples to make the food-science Enemies List—fat, salt, eggs—should warn of the folly of declaring the food science settled.

Before we remove all trans fats from our diets, perhaps we could exercise a long-forgotten principle taught to us by our parents and grandparents: “Everything in moderation.” Instead of banning trans fats completely, Americans and food manufacturers can each take a lesson in exercising some moderation. Trans fats don’t have to be totally banned from our diets, nor should they—or any food, for that matter—dominate them.

For most Americans, the difference between copious amounts of lard or trans fats in their diets won’t be substantive—at least as far as their clogging arteries are concerned. But for those who follow a religious diet like kashrut or halal, re-including lard could become a serious hindrance to food preparation and religious observance.

Bethany Mandel is a stay-at-home mother of three children under four and a writer on politics and culture. She is a senior contributor to The Federalist, a columnist for the Jewish Daily Forward, and a contributor at Acculturated. She lives with her husband, Seth, in New Jersey. You can follow her on Twitter @BethanyShondark.